
Description of measuring mode "Level"
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MA Start of scale value p Pressure
ME Full scale value PV Primary variable
Figure 7-10 "Analog output" block
Note
If, when setting the analog output, the values for the start of scale value zero and the full
scale value are more than 20% below or above the limit values of the set PV (set using the
variable
mapper), the values will be rejected by the device. The values configured previously
are retained. Similarly, the span must not fall below the minimum.
Minimum span = ME - MA
The square root extracting function can only be selected in the "Pressure" measuring mode.
The "srlin2" square root extracting function is set as default in the "Flow rate" measuring mode.
7.3.11 Scaling the display value
Introduction
You
can scale the value shown in the display as you wish and allocate it any unit of 5 characters.
The scaling of the value is independent of the selection of the measuring mode selector, the
primary variable (PV) and the display unit defined. Use the "Display settings" item in
SIMATIC PDM or the HART communicator for this purpose.
The percent value of the PV is the basis for this scaling. This percent value is also used to
scale the current output. In SIMATIC PDM, this item is referred to as "Setting the PV output
scaling". After selecting the "Display settings" menu item, you must enter a start-of-scale value,
a full-scale value and a unit string.
This display option has the highest priority amongst all options. A switch over to %, mA or any
other unit is not possible in this status. You need to deactivate the LCD scaling again for this
purpose.
Operating functions through HART
7.3 Selecting the measuring modes
SITRANS P, DS III series with HART
Operating Instructions, 09/2012, A5E00047092-08 115
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